1. Field of the Invention
Embodiments of the invention relate generally to a voltage supply circuit and, and more particularly to an integrated circuit including the same.
2. Description of the Related Art
An integrated circuit is a functional and complex electronic element or system having an ultra-small structure in which lots of electronic circuit elements are coupled on or to one substrate. The integrated circuit or device includes a voltage supply circuit for supplying a power source for an operation.
Low voltage is typically supplied to an ultra-small integrated circuit. The integrated circuit, however, frequently requires high voltage for an internal operation. Accordingly, a voltage supply circuit used in the integrated circuit includes a pump circuit for generating high voltage that may be achieved by pumping a low input power source voltage. The time that it takes an integrated circuit to perform operations may vary according to how quickly the pump circuit raises the low input power source voltage to a target voltage.
For example, when data is programmed in an integrated circuit, such as a semiconductor memory device, the total time taken to perform a program operation may be reduced if there is a reduction in the time to generate and supply a high voltage needed for the program operation.
In order to control the operating time, a rising time of voltage outputted from the pump circuit may need to be controlled.
The pump circuit is designed according to a load of an output node. Accordingly, when a voltage supply circuit included in the integrated circuit is designed, the rising time of the output voltage may be set through accurate modeling of the voltage supply circuit. If modeling is not accurate, the integrated circuit may not operate normally because the rising time of the output voltage is not set as desired, thereby requiring correction of the inaccurate modeling (that is, a revision). The correction process is a complicated and time consuming task.